Compared with cathode ray tube (CRT) displays or thin film transistor-liquid crystal displays (TFT-LCDs), organic light-emitting diode (OLED) displays have the characteristics of being lighter and thinner appearance design, wider viewing angle, faster response, lower power consumption and the like, and hence have been much concerned as the next-generation display device.
An OLED device is a self-luminous device and generally comprises a cathode, an anode arranged opposite to the cathode, and an organic light emitting layer disposed between the cathode and the anode. When the OLED device operates, a voltage is applied between the cathode and the anode so as to generate an electric field at both ends of the organic light emitting layer disposed between the cathode and the anode, and hence electrons and holes can be recombined with each other in the organic light emitting layer and hence light emits. Display effect of the OLED display device can be controlled by controlling the voltages applied to pixel electrodes via an array substrate with circuit units.
In conventional techniques, an OLED display device comprises an OLED device and a thin-film transistor (TFT) array substrate. An organic light emitting layer of the OLED device is disposed on a surface of a pixel electrode of the TFT array substrate. The pixel electrode can be used as a cathode or an anode of the OLED device. Under influence of capacitance and a magnetic field due to currents in the TFT structure, the light-emitting effect of the light emitting layer is poor. Moreover, as the pixel electrode of the TFT structure has a rough surface, a base of the pixel electrode should be subject to surface treatment before coating a light emitting layer, and hence the manufacturing process is complicated and the cost increases.